title: ABO fetomaternal compatibility poses a risk for massive fetomaternal transplacental hemorrhage.
abstract: OBJECTIVE
  Severe fetomaternal transplacental hemorrhage increases the risk of fetal anemia. In the third trimester, the syncytiotrophoblast becomes thinner, especially in areas where it comes into intimate contact with villous capillaries, and forms a vasculosyncytial membrane. Our aim was to determine whether ABO compatibility puts the fetus at a greater risk of severe fetomaternal hemorrhage.
  
  
  METHODS
  Case study.
  
  
  METHODS
  A tertiary care center. Sample and methods. Between 2003 and 2007, we evaluated eight cases of severe fetomaternal transfusion. The Kleihauer-Betke test was used for diagnosis of fetomaternal hemorrhage. We evaluated blood group compatibility between the mother and fetus and assessed the perinatal outcome. The Fischer's factorial test was used for testing a hypothesis.
  
  
  RESULTS
  The incidence of adverse outcomes following transplacental hemorrhage was 75% (six of eight). There were two perinatal deaths and four infants were affected by post-hypoxic damage of varying severity. Fetomaternal ABO compatibility was present in seven of the eight cases. The risk of severe fetomaternal hemorrhage was significantly increased when there was ABO compatibility between the mother and fetus. This was associated with a very poor perinatal outcome.
  
  
  CONCLUSIONS
  We recommend that resuscitation in utero by intrauterine transfusion should be considered before the 33rd week of gestation in cases of severe fetal anemia. In later gestation, urgent cesarean section is required with adequate resuscitation of the newborn.
authors.affiliation: 1Department of Obstetrics and Gynecology, General Faculty Hospital and 1st Faculty of Medicine, Charles University, Prague, Czech Republic. zzizka@lf1.cuni.cz
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Zizka
authors.forename: Tomas
authors.initials: T
authors.lastname: Fait
authors.forename: Hana
authors.initials: H
authors.lastname: Belosovicova
authors.forename: Lucia
authors.initials: L
authors.lastname: Haakova
authors.forename: Michal
authors.initials: M
authors.lastname: Mara
authors.forename: Marie
authors.initials: M
authors.lastname: Jirkovska
authors.forename: Jan Evangelista
authors.initials: JE
authors.lastname: Jirasek
authors.forename: Lucie
authors.initials: L
authors.lastname: Bartosova
authors.forename: Pavel
authors.initials: P
authors.lastname: Calda
mesh_terms: D000017:ABO Blood-Group System / Q000502:physiology*; D001805:Blood Transfusion, Intrauterine; D005260:Female; D005331:Fetomaternal Transfusion / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D005333:Fetus; D006801:Humans; D007231:Infant, Newborn; D008854:Microscopy, Electron; D010920:Placenta / Q000503:physiopathology / Q000648:ultrastructure; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000209:etiology*; D011263:Pregnancy Trimester, Third
chemical_list: D000017:ABO Blood-Group System